(b)
Cube each side.
Apply the exponents.
Standard form
Factor.
or Zero-factor property
or Solve.
CHECK
Let Let
✓ True ✓ True
Both proposed solutions check, so the solution set is 5 - 1, 27 6. NOW TRY
1 = 1 9 = 9
231 231 23729 23729
x=-1. x=27.
231 - 122 23261 - 12 + 27 2312722 23261272 + 27
23 x^2 = 2326 x+ 27 23 x^2 = 2326 x+ 27
x=- 1 x= 27
x+ 1 = 0 x - 27 = 0
1 x+ 121 x- 272 = 0
x^2 - 26 x- 27 = 0
x^2 = 26 x+ 27
A 23 x^2 B
3
=A 2326 x+ 27 B
3
23 x^2 = 2326 x+ 27
536 CHAPTER 8 Roots and Radicals
NOW TRY
EXERCISE 8
Solve each equation.
(a)
(b) 232 x^2 = 2310 x- 12
238 x- 3 = 234 x
NOW TRY ANSWERS
- (a)E^34 F (b) 5 2, 3 6
Complete solution available
on the Video Resources on DVD
8.6 EXERCISES
Solve each equation. See Examples 1–4.
- 23 m+ 3 = 25 m- 1 29. 23 x- 8 =- 2 30. 26 t+ 4 =- 3
22 x+ 2 = 23 x- 5 2 x+ 2 = 22 x- 5 25 x- 5 = 24 x+ 1
x= 2 x^2 - 2 x- 6 7 x= 249 x^2 + 2 x- 10 6 x= 236 x^2 + 5 x- 5
23 x- 5 = 22 x+ 1 25 x+ 2 = 23 x+ 8 k= 2 k^2 - 5 k- 15
217 t- 4 = 42 t 52 x= 210 x+ 15 42 x= 220 x- 16
2 w- 4 = 7 2 t + 3 = 10 210 x- 8 = 32 x
22 t+ 3 = 0 25 x- 4 = 0 2 t =- 5 2 p=- 8
2 r- 4 = 9 2 x- 12 = 3 24 - t= 7 29 - s= 5
2 x= 7 2 x= 10 2 x+ 2 = 3 2 x+ 7 = 5
31.Concept Check Consider the following
“solution.”WHAT WENT WRONG?
Square each side.
Distributive property
Subtract 1.
Multiply by
Solution set: 5 - 156
x=- 15 - 1.
- x= 15
- x+ 1 = 16
- 1 x- 12 = 16
- 2 x- 1 =- 4
32.Concept Check The first step in solving
the equation
is to square each side of the equation.
Errors often occur in solving equations
such as this one when the right side of
the equation is squared incorrectly. What
is the square of the right side?
22 x+ 1 =x- 7
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